Identifying robust transport features of the upper tropical troposphere

Spatial patterns of boundary layer influence at 100 hPa are nevertheless robust. Detrainment-to-tropopause transport times are robust despite substantial model-to-model variations of convective detrainment height because ascent rates are faster at low altitudes than at high altitudes. Detrainment-to-tropopause transport also has robust horizontal spatial patterns for both convective sources and convective influence, particularly during boreal winter.

Most model-to-model discrepancies occur at small spatial scales and are associated with differing distributions of convection. The location of maximum convective influence associated with the Asian summer monsoon is a notable exception. This exceptionally large discrepancy is associated primarily with radiative ascent.

The fact that the observed maxima of important tropospheric constituents are collocated with the maximum convective influence for the diabatic calculations but not for the kinematic calculations suggests that diabatic trajectories could be more reliable in this region.